Plastic corrugated sheathing hoses per se have long been known (for instance, from German Pat. No. 1 218,574) and are used successfully in the most various ways in electric installation, for instance in homes or for outdoor lines buried underground. It is also known per se to provide such corrugated sheathing hoses with a longitudinal slit on the side, in order to be able thereby to wrap laid cable segments with it or to make repairs of damaged segments of corrugated hose.
From German laid-open application DE-OS No. 31 00 944, a flexible protective hose having a longitudinal slit on the side is known, which is conceived particularly for repair purposes. This protective hose is supposed to have the greatest possible bending elasticity and is therefore provided with slits transverse to the longitudinal axis as well. This provision, however, necessitates wrapping the flexible hose, after installation, with a self-welding adhesive tape or the like, in order to attain the desired waterproofing and gas-tightness.